Cognitive decline in an elderly hospitalized patient with primary leptomeningeal melanomatosis.

Delirium is one of the most common disorders in hospitalized patients. The authors present the case of an elderly male patient with postoperative cognitive decline that did not resolve with the conventional treatment. The diagnosis was only established on autopsy. A 75-year-old man was evaluated after a fall. Initial evaluation revealed voluntary guarding in the right epigastric region, and free air was detected under the right hemidiaphragm on abdominal radiography. An exploratory laparotomy revealed a perforation that had apparently sealed off. After surgery, he had initial improvement toward baseline; however, after several days, his postoperative course was complicated by a progressive deterioration in mental status, recurrent seizures, and aspiration pneumonia. Computed tomographic scan of the brain showed communicating hydrocephalus. Examination of the cerebrospinal fluid revealed an elevated opening pressure and elevated protein. His mental status continued to deteriorate, and he died. Autopsy revealed the pathologic diagnosis of primary leptomeningeal melanomatosis.